Create a proper package structure

fetch/fetch.go

@@ -1,8 +1,9 @@
-package main
+package fetch
 
 import (
 	"encoding/json"
 	"fmt"
+	"github.com/tweag/gomod2nix/types"
 	"golang.org/x/mod/modfile"
 	"golang.org/x/tools/go/vcs"
 	"io/ioutil"
@@ -10,14 +11,28 @@ import (
 	"sort"
 )
 
-type Package struct {
-	GoPackagePath string
-	URL           string
-	Rev           string
-	Hash          string
+type packageJob struct {
+	importPath    string
+	goPackagePath string
+	rev           string
 }
 
-func FetchPackages(goModPath string, goSumPath string, numWorkers int, keepGoing bool) ([]*Package, error) {
+type packageResult struct {
+	pkg *types.Package
+	err error
+}
+
+func worker(id int, replace map[string]string, jobs <-chan *packageJob, results chan<- *packageResult) {
+	for j := range jobs {
+		pkg, err := fetchPackage(j.importPath, j.goPackagePath, j.rev)
+		results <- &packageResult{
+			err: err,
+			pkg: pkg,
+		}
+	}
+}
+
+func FetchPackages(goModPath string, goSumPath string, numWorkers int, keepGoing bool) ([]*types.Package, error) {
 
 	// Read go.mod
 	data, err := ioutil.ReadFile(goModPath)
@@ -74,7 +89,7 @@ func FetchPackages(goModPath string, goSumPath string, numWorkers int, keepGoing
 	}
 	close(jobs)
 
-	var pkgs []*Package
+	var pkgs []*types.Package
 	for i := 1; i <= numJobs; i++ {
 		result := <-results
 		if result.err != nil {
@@ -96,7 +111,7 @@ func FetchPackages(goModPath string, goSumPath string, numWorkers int, keepGoing
 	return pkgs, nil
 }
 
-func fetchPackage(importPath string, goPackagePath string, rev string) (*Package, error) {
+func fetchPackage(importPath string, goPackagePath string, rev string) (*types.Package, error) {
 	repoRoot, err := vcs.RepoRootForImportPath(importPath, false)
 	if err != nil {
 		return nil, err
@@ -133,7 +148,7 @@ func fetchPackage(importPath string, goPackagePath string, rev string) (*Package
 		return nil, err
 	}
 
-	return &Package{
+	return &types.Package{
 		GoPackagePath: goPackagePath,
 		URL:           repoRoot.Repo,
 		// It may feel appealing to use output.Rev to get the full git hash

fetch/sum.go

@@ -1,4 +1,4 @@
-package main
+package fetch
 
 import (
 	"bytes"

main.go

@@ -3,30 +3,10 @@ package main // import "github.com/tweag/gomod2nix"
 import (
 	"flag"
 	"fmt"
+	"github.com/tweag/gomod2nix/fetch"
 	"path/filepath"
 )
 
-type packageJob struct {
-	importPath    string
-	goPackagePath string
-	rev           string
-}
-
-type packageResult struct {
-	pkg *Package
-	err error
-}
-
-func worker(id int, replace map[string]string, jobs <-chan *packageJob, results chan<- *packageResult) {
-	for j := range jobs {
-		pkg, err := fetchPackage(j.importPath, j.goPackagePath, j.rev)
-		results <- &packageResult{
-			err: err,
-			pkg: pkg,
-		}
-	}
-}
-
 func main() {
 
 	flag.Parse()
@@ -35,7 +15,7 @@ func main() {
 	keepGoing := true
 	directory := "./"
 
-	pkgs, err := FetchPackages(filepath.Join(directory, "go.mod"), filepath.Join(directory, "go.sum"), numWorkers, keepGoing)
+	pkgs, err := fetch.FetchPackages(filepath.Join(directory, "go.mod"), filepath.Join(directory, "go.sum"), numWorkers, keepGoing)
 	if err != nil {
 		panic(err)
 	}

types/types.go

@@ -0,0 +1,8 @@
+package types
+
+type Package struct {
+	GoPackagePath string
+	URL           string
+	Rev           string
+	Hash          string
+}